1. Field of the Invention
The present invention is generally in the field of fabrication of semiconductor devices. More particularly, the invention is in the field of fabrication of conductive structures in semiconductor wafers.
2. Background Art
The semiconductor devices, such as bipolar junction transistors (BJTs) and field effect transistors (FETs) that are fabricated using low-cost silicon technology, continue to increase in frequency, speed, and power. As a result, semiconductor devices, such as BJTs and FETs that are fabricated on a silicon wafer, also require conductive structures that provide effective and reduced impedance ground paths for the substrates of these semiconductor devices. For example, an application using silicon-based BJTs can require a conductive structure that provides a reduced impedance path between emitter and ground, while silicon-based FETs can require a conductive structure that provides a lower impedance path between source and ground.
Also, semiconductor devices, such as BJTs and FETs that operate with a high power consumption, require conductive structures that provide more efficient thermal conduits to transfer heat away from the semiconductor device. For example, silicon-based BJTs having increased power-handling capability can require conductive structures that provide more efficient heat transfer to prevent excessive heat from damaging the transistor and/or resulting in degraded device performance.
Thus, there is a need in the art for an effective method for fabricating a conductive structure that provides a reduced impedance ground path for the substrates of semiconductor devices and a more efficient thermal conduit for semiconductor devices.